The invention relates to a spring-support mechanism for a parallel robot with constant force. Specifically, a spring-support mechanism for parallel robot with constant force as mentioned in the invention transforms elastic force of the springs into thrust force on the moving frame of the parallel robot, and this thrust force has a constant magnitude in the workspace of the moving frame.
Parallel robot is supported by a spring without a transforming mechanism (FIG. 1), this spring generates a thrust force varying with the compression length of the spring. So in the whole workspace of parallel robot, this thrust force is greatly altered by the position of the moving frame. This support force does not diminish the effect of loading on the robot's actuator, significantly. Direct spring support is only suitable for small displacement robots, thrust force of this spring doesn't change a lot in a small workspace. While robots with large displacement are difficult to apply, effectively.
Therefore, this invention comprises a mechanism that transforms the elastic force of the springs into the thrust force of the parallel robot to balance the gravity of the load placed on the moving frame. By creating constant thrust, it will greatly reduce impact of gravity of load on the parallel robot's actuator. Especially for robots where acceleration of the moving frame is smaller than gravity acceleration, the main driving force on the driving actuators is the gravity of the load, the thrust force generated from the spring-support mechanism eliminates most of the gravity effect of the load. Consequently, the force on the driving actuators is mainly a force to accelerate the movement of the moving frame (not including the gravity of load).